The End Justifies the Means: Chagas Disease from a Perspective of the Host-Trypanosoma cruzi Interaction

The neglected Chagas disease (CD) is caused by the protozoan parasite Trypanosoma cruzi. Despite CD dispersion throughout the world, it prevails in tropical areas affecting mainly poor communities, causing devastating health, social and economic consequences. Clinically, CD is marked by a mildly symptomatic acute phase, and a chronic phase characterized by cardiac and/or digestive complications. Current treatment for CD relies on medications with strong side effects and reduced effectiveness. The complex interaction between the parasite and the host outlines the etiology and progression of CD. The unique characteristics and high adaptability of T. cruzi, its mechanisms of persistence, and evasion of the immune system seem to influence the course of the disease. Despite the efforts to uncover the pathology of CD, there are many gaps in understanding how it is established and reaches chronicity. Also, the lack of effective treatments and protective vaccines constitute challenges for public health. Here, we explain the background in which CD is established, from the peculiarities of T. cruzi molecular biology to the development of the host's immune response leading to the pathophysiology of CD. We also discuss the state of the art of treatments for CD and current challenges in basic and applied science.

Chagas Disease in Europe

Chagas disease is currently present in many non-endemic countries and remains a neglected tropical disease globally. A review of the literature identified significant gaps and scarcity of updated information from European countries, with most studies reporting data from Spain and Italy. The index of underdiagnosis may be as high as 70%, affecting mainly females of child-bearing age. Standardized screening of fertile, non-pregnant, women from endemic countries and subsequent treatment is considered an essential strategy to control transmission and prevent new cases, yet no uniform legislation for screening risk groups exists. There is heterogeneity in Europe in terms of preventive strategies to avoid transfusion-related transmission of Chagas disease, not necessarily in line with the European directives, with some countries conducting systematic screening for T. cruzi infection in blood donors, whilst others rely on pre-transfusion questionnaires. The growing burden of the infection in resource-rich areas may provide an opportunity for progress in certain aspects of control and prevention. Options for improving screening strategies, management and linkage to care are reviewed.

Genomic surveillance: a potential shortcut for effective Chagas disease management

Chagas disease is an enduring public health issue in many Latin American countries, receiving insufficient investment in research and development. Strategies for disease control and management currently lack efficient pharmaceuticals, commercial diagnostic kits with improved sensitivity, and vaccines. Genetic heterogeneity of Trypanosoma cruzi is a key aspect for novel drug design since pharmacological technologies rely on the degree of conservation of parasite target proteins. Therefore, there is a need to expand the knowledge regarding parasite genetics which, if fulfilled, could leverage Chagas disease research and development, and improve disease control strategies. The growing capacity of whole-genome sequencing technology and its adoption as disease surveillance routine may be key for solving this long-lasting problem.

Evaluation of the Chagas VirClia® and Chagas TESA VirClia® for the Diagnosis of Trypanosoma cruzi Infection

Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, is an important problem of public health even in regions where it is not endemic. Spain ranks second worldwide in terms of imported cases of T. cruzi infection in the chronic phase. The diagnosis in this stage is made via the detection of antibodies against T. cruzi. Therefore, we aimed to evaluate the sensitivity and specificity of two fully automated chemiluminescence immunoassays, Chagas VirClia^® (CHR), which uses a mixture of recombinant antigens, and Chagas TESA VirClia^® (TESA), the first chemiluminescence assay based on excretion-secretion antigens of trypomastigotes, both designed in monotest format. A retrospective case-control study was performed using 105 well-characterized samples: 49 from patients with CD, 22 from uninfected individuals, and 32 from patients with other pathologies. Sensitivity was 98% for CHR and 92% for TESA. In contrast, the specificity in both was 100%. Cross-reactivity was observed in leishmaniasis (2/10). CHR meets the criteria to become a tool for serological screening, while TESA has the potential for confirmation and cross-reaction discrimination. The monotest format allows its application in laboratories with a small number of samples. The high specificity of both assays is useful in areas where leishmaniasis is endemic.

Chagas Disease and Transfusion Risk in Italy: The Results of a National Survey

BACKGROUND

Universal serological screening in endemic areas is essential for preventing Chagas disease transmission by transfusions, while in non-endemic areas, screening is provided only to donors exposed to the infection risk. In this respect, in order to ensure high and uniform standards of quality and safety of blood components, the Italian National Blood Centre conducted a survey to detect information on management of donors at risk of Chagas disease and on the current transfusion risk.

METHODS

The National Blood Centre conducted a survey on preventive measures for Chagas disease in the years 2020-2021.

RESULTS

Survey results are broadly representative of the national situation; out of 24,269 tested donors, only 15 donors were confirmed positive (0.4 out of 100,000 donors). This rate is lower than the number of positive donors (72/100,000) for transfusion transmissible infections (HIV, HBV, HCV, and T. pallidum) in the same period. Furthermore, the number of T. cruzi positive blood donors is lower than the T. cruzi positive subjects in the general population.

CONCLUSIONS

In Italy, T. cruzi infection transfusion risk may be considered still very low, and this is confirmed by the absence of documented transfusion transmission.

Adding a piece to the puzzle of Latin American blood donors and the potential risk of Trypanosoma cruzi transmission in Germany

Introduction

Chagas disease (CD) is caused by the Trypanosoma cruzi (T. cruzi) infection and has become a global health concern due to population mobility, as well as non-vectorial transmission routes. Several countries outside Latin America (LA) have reported transfusion-associated transmission, but equivalent studies in Germany are lacking. This study aims to collect first data on the risk of transfusion associated transmission as well as LA blood donors originating from CD endemic countries in Germany

Materials and methods

A total of 305 blood donors who were assumed to be at risk for T. cruzi infection were retrospectively (267) as well as prospectively (38) selected at German blood donation sites in Bavaria and Berlin, and all retrospectively as well as 27 prospectively selected were serologically screened. Prospective study subjects additionally filled out a questionnaire.

Results

All samples tested seronegative for T. cuzi specific antibodies. Prospectively enrolled study subjects all had high socio-economic status including good education. Knowledge regarding CD was limited but willingness to donate frequently was high. Blood donation rates from donors born in LA countries seem to increase from 2015.

Discussion

Although no transfusion associated T. cruzi infection has been documented in Germany, it has likely already happened unnoticed, or will do in the near future. Performing risk-adapted serology-based blood donor screenings in Germany could avoid transfusion-associated transmission events as well as contribute to active case detection. Moreover, larger, and ongoing studies are needed to increase the evidence base as well as end the neglect of CD in Germany.

Worldwide Control and Management of Chagas Disease in a New Era of Globalization: a Close Look at Congenital Trypanosoma cruzi Infection

Population movements have turned Chagas disease (CD) into a global public health problem. Despite the successful implementation of subregional initiatives to control vectorial and transfusional Trypanosoma cruzi transmission in Latin American settings where the disease is endemic, congenital CD (cCD) remains a significant challenge. In countries where the disease is not endemic, vertical transmission plays a key role in CD expansion and is the main focus of its control. Although several health organizations provide general protocols for cCD control, its management in each geopolitical region depends on local authorities, which has resulted in a multitude of approaches. The aims of this review are to (i) describe the current global situation in CD management, with emphasis on congenital infection, and (ii) summarize the spectrum of available strategies, both official and unofficial, for cCD prevention and control in countries of endemicity and nonendemicity. From an economic point of view, the early detection and treatment of cCD are cost-effective. However, in countries where the disease is not endemic, national health policies for cCD control are nonexistent, and official regional protocols are scarce and restricted to Europe. Countries of endemicity have more protocols in place, but the implementation of diagnostic methods is hampered by economic constraints. Moreover, most protocols in both countries where the disease is endemic and those where it is not endemic have yet to incorporate recently developed technologies. The wide methodological diversity in cCD diagnostic algorithms reflects the lack of a consensus. This review may represent a first step toward the development of a common strategy, which will require the collaboration of health organizations, governments, and experts in the field.

International survey of strategies to mitigate transfusion-transmitted Trypanosoma cruzi in non-endemic countries, 2016-2018

BACKGROUND AND OBJECTIVES

Chagas disease, caused by Trypanosoma cruzi, is endemic to Mexico, Central and South America. While initially limited to the Americas, emigration of infected persons triggered geographically broader blood safety challenges. To mitigate transfusion-transmitted Chagas (TTC), transfusion services implemented approaches including risk factor questions and serologic testing. We sought to understand and compare strategies in non-endemic countries.

MATERIALS AND METHODS

Transfusion services in International Society of Blood Transfusion (ISBT)-affiliated organizations and members of the ISBT Working Party on Transfusion-Transmitted Infectious Diseases were invited to complete an online survey on T. cruzi mitigation strategies. The survey queried about cases of TTC, risk factors, testing methodology, educational materials, pathogen reduction, donor/product management, donor deferral and perceived public health concerns surrounding TTC.

RESULTS

Responses were received from 27 institutions in 22 countries. Most countries (77.3%) reported no historical TTC cases, while 18.2% reported 1-5 cases and 4.5% reported 6-10 cases. Concern about Chagas among the general public and public health authorities was low, but 12 of 25 blood centres reported moderate/high concern. Overall, 17 countries mitigated for TTC: 15 used risk factor questions and 10tested for T. cruzi antibodies. Ten countries used pathogen reduction but not specifically to prevent TTC.

CONCLUSION

While Chagas is rarely cited as a public health concern, blood centres in many non-endemic countries, including those outside the Americas, implemented measures to mitigate risk. Mitigation focussed on risk factors associated with Latin American immigrants and serologic testing. Thus, despite the rarity of TTC, many non-endemic countries continue to address it as an ongoing blood safety risk.

Screening Program for Imported Diseases in Immigrant Women: Analysis and Implications from a Gender-Oriented Perspective

The female immigrant population is especially vulnerable to imported diseases. We describe the results of a prospective screening program for imported diseases performed in immigrant female patients. The protocol included tests for HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), Treponema pallidum, Trypanosoma cruzi, Strongyloides stercoralis and Schistosoma spp., intestinal parasites, malaria, and the detection of microfilaremia, according to the patient's origin. Six hundred eleven patients were studied. The most frequent imported diseases were intestinal parasitosis (39.4%), followed by syphilis (14.6%), HIV infection (9%), chronic HCV (5%), and HBV (3.3%). Most of the cases of HIV (78%) and HBV (85%) were diagnosed in patients aged between 16 and 45 years. Hepatitis C virus appeared mostly in patients in the 46- to 65-year range (P = 0.001; odds ratio [OD]: 3.667 [1.741-7.724]) or older than 65 years (P = 0.0001; OR: 26.350 [7.509-92.463]). Syphilis was diagnosed more frequently in patients older than 46 years (P = 0.0001; OR: 4.273 [2.649-6.893]). Multivariate analysis confirmed a greater presence of HCV infection (P = 0.049) and syphilis (P = 0.0001) in patients aged between 46 and 65 years. In 15.4% of patients, screening did not find any pathology. These data show a high prevalence of imported diseases in the female immigrant population, which may have serious consequences in terms of morbimortality and vertical transmission. Our results encourage the establishment of policies of active screening both in women of childbearing age and within the specific pregnancy screening programs.

Structural bases that underline Trypanosoma cruzi calreticulin proinfective, antiangiogenic and antitumor properties

Microbes have developed mechanisms to resist the host immune defenses and some elicit antitumor immune responses. About 6 million people are infected with Trypanosoma cruzi, the protozoan agent of Chagas' disease, the sixth neglected tropical disease worldwide. Eighty years ago, G. Roskin and N. Klyuyeva proposed that T. cruzi infection mediates an anti-cancer activity. This observation has been reproduced by several other laboratories, but no molecular basis has been proposed. We have shown that the highly pleiotropic chaperone calreticulin (TcCalr, formerly known as TcCRT), translocates from the parasite ER to the exterior, where it mediates infection. Similar to its human counterpart HuCALR (formerly known as HuCRT), TcCalr inhibits C1 in its capacity to initiate the classical pathway of complement activation. We have also proposed that TcCalr inhibits angiogenesis and it is a likely mediator of antitumor effects. We have generated several in silico structural TcCalr models to delimit a peptide (VC-TcCalr) at the TcCalr N-domain. Chemically synthesized VC-TcCalr did bind to C1q and was anti-angiogenic in Gallus gallus chorioallantoic membrane assays. These properties were associated with structural features, as determined in silico. VC-TcCalr, a strong dipole, interacts with charged proteins such as collagen-like tails and scavenger receptors. Comparatively, HuCALR has less polarity and spatial stability, probably due to at least substitutions of Gln for Gly, Arg for Lys, Arg for Asp and Ser for Arg that hinder protein-protein interactions. These differences can explain, at least in part, how TcCalr inhibits the complement activation pathway and has higher efficiency as an antiangiogenic and antitumor agent than HuCALR.

Apolipoprotein A1 and Fibronectin Fragments as Markers of Cure for the Chagas Disease

Chagas disease (CD), endemic from Latin America, affects more than 8 million people, and the disease keeps spreading around the world due to population migrations. The treatment options for CD are currently limited to two drugs, benznidazole (BZ) and nifurtimox (Nfx), which are often unsatisfactory in chronically infected patients. To date, the only accepted marker of the cure is seroconversion (the disappearance of Trypanosoma cruzi antibodies in the patient's serum), which can take decades to occur, if ever. The lack of posttreatment test-of-cure often prevents appropriate patient counseling and limits the development of new drugs. Without a doubt, reliable biomarkers for parasitological cure are urgently needed. Several pieces of evidence suggest that apolipoprotein A1 and fibronectin fragments are produced during the infection as part of the process of T. cruzi cell invasion and can thus be used as its surrogate biomarkers. In this chapter, we present a standardized method to evaluate these fragments in serum using mass spectrometry and immunoblotting in CD patients for diagnosis, prognosis, and treatment assessment purposes.

Trypanosoma cruzi infection in transfusion medicine

INTRODUCTION

Infection by Trypanosoma cruzi is challenging to blood bank supplies in terms of accurate diagnosis, mostly due to its clinical complexity. Infected individuals may remain asymptomatic for years, albeit they may have circulating parasites potentially transferable to eventual receptors of a transfusion.

OBJECTIVE

Although risk donors are systematically excluded through a survey, an important residual risk for transmission remains, evidencing the need to implement additional actions for the detection of T. cruzi in blood banks.

METHOD

A review of the scientific literature is presented with the objective of identifying relevant publications on this subject.

RESULTS

We discuss the diagnostic considerations of this chronic infection on transfusion medicine and some recent advances in the processing of blood and derivatives units.

CONCLUSION

Finally, recommendations are made on how the transmission of T. cruzi can be avoided through the implementation of better diagnostic and pathogen control measures at blood banks.

Chagas disease: a report of 17 suspected cases in Japan, 2012-2017

Background

There are no reports on the prevalence of Chagas disease in Japan. Furthermore, screening programs and access to diagnosis and treatment have not been established. This study aimed to clarify the prevalence of Chagas disease among suspected cases in Japan and provide the reference data required for disease control.

Methods

Seventeen patients with suspected Chagas disease in Japan between 2012 and 2017 were included in the study. Patients were diagnosed with Chagas disease based on the two different serological tests for antibodies to Trypanosoma cruzi. Real-time polymerase chain reaction assay and blood culture techniques were performed to confirm T. cruzi parasitemia.

Results

Of the 17 patients, 11 (64.7%) were immigrants from Latin America. Ultimately, 6 patients (35.3%) were diagnosed with Chagas disease. Of these 6 patients, median age was 53.5 years, 5 patients were immigrants from Latin American, and 1 was Japanese who had a congenital infection. T. cruzi parasitemia was confirmed in 4 patients (66.7%), and 5 (83.3%) were in the chronic phase (Chagas cardiomyopathy, 4; megacolon, 1). Two patients (33.3%) commenced benznidazole treatment.

Conclusion

Our study showed that some patients of Chagas disease living in Japan are already in the chronic phase at diagnosis because of substantial diagnostic delays. Further epidemiological studies on the prevalence of Chagas disease and systematic screening programs for the Latin American population are needed.

Discovery of new potent hits against intracellular Trypanosoma cruzi by QSAR-based virtual screening

Chagas disease is a neglected tropical disease (NTD) caused by the protozoan parasite Trypanosoma cruzi and is primarily transmitted to humans by the feces of infected Triatominae insects during their blood meal. The disease affects 6-8 million people, mostly in Latin America countries, and kills more people in the region each year than any other parasite-born disease, including malaria. Moreover, patient numbers are currently increasing in non-endemic, developed countries, such as Australia, Japan, Canada, and the United States. The treatment is limited to one drug, benznidazole, which is only effective in the acute phase of the disease and is very toxic. Thus, there is an urgent need to develop new, safer, and effective drugs against the chronic phase of Chagas disease. Using a QSAR-based virtual screening followed by in vitro experimental evaluation, we report herein the identification of novel potent and selective hits against T. cruzi intracellular stage. We developed and validated binary QSAR models for prediction of anti-trypanosomal activity and cytotoxicity against mammalian cells using the best practices for QSAR modeling. These models were then used for virtual screening of a commercial database, leading to the identification of 39 virtual hits. Further in vitro assays showed that seven compounds were potent against intracellular T. cruzi at submicromolar concentrations (EC₅₀ < 1 μM) and were very selective (SI > 30). Furthermore, other six compounds were also inside the hit criteria for Chagas disease, which presented activity at low micromolar concentrations (EC₅₀ < 10 μM) against intracellular T. cruzi and were also selective (SI > 15). Moreover, we performed a multi-parameter analysis for the comparison of tested compounds regarding their balance between potency, selectivity, and predicted ADMET properties. In the next studies, the most promising compounds will be submitted to additional in vitro and in vivo assays in acute model of Chagas disease, and can be further optimized for the development of new promising drug candidates against this important yet neglected disease.

Validation of Apolipoprotein A-1 and Fibronectin Fragments as Markers of Parasitological Cure for Congenital Chagas Disease in Children Treated With Benznidazole

Background

No reliable tests or validated biomarkers exist to ensure parasitological cure following treatment of Chagas disease (CD) patients chronically infected with Trypanosoma cruzi. As seroreversion, the only marker of cure, happens more quickly in children, we investigated the correlation between previously identified biomarkers and seroreversion in children.

Methods

Thirty CD children (age 1 month to 10 years) diagnosed as T. cruzi positive (time point S0) were treated with benznidazole (BZ) 5–8 mg/kg/d for 60 days. At least 2 serological tests were used to evaluate treatment efficacy from the end of treatment (S1) until seroreversion (S2). Thirty children (age 1 month to 10 years) and 15 adults were used as healthy controls (HCs). Immunoblot and a proteomic-based assay were used to validate previously identified fragments of apolipoprotein A-1 (ApoA1) and fibronectin (FBN) as CD biomarkers.

Results

Correlation between seroreversion and absence of ApoA1 and FBN fragments by immunoblot was observed in 30/30 (100%) and 29/30 (96.6%) CD children, respectively. ApoA1 and FBN fragments were absent at the end of BZ treatment in 20/30 (66.6%) and 16/30 (53.3%) children, respectively. Absence of fragments in serum profiles was confirmed by mass spectrometry. Using intact protein analysis, a 28 109-Da protein identified as full-length ApoA1 by tandem mass spectrometry was detected in HC serum samples.

Conclusions

These data confirm that ApoA1 and FBN fragments can discriminate between healthy and T. cruzi–infected samples. Correlation with seroreversion was shown for the first time; results suggest predictive capacity potentially superior to serology, making them potentially useful as surrogate biomarkers.

Detection of Trypanosoma cruzi antibodies in multitransfused patients in Colombia

INTRODUCTION

Chagas disease is a public health problem in Latin America. Even though vector-borne infection is the most important transmission mode for this disease, other modes such as transfusions require evaluation.

OBJECTIVE

To describe the prevalence of T. cruzi infection in multitransfused patients.

MATERIALS AND METHODS

We detected IgG antibodies against T. cruzi by two immunoassays in samples from multitransfused patients in four hospitals located in Bogotá and Medellín, Colombia. We analyzed the association with known risk factors, and we calculated the odds ratios (OR) with 95% confidence intervals using Stata 11™ statistical software.

RESULTS

In total, 479 samples were tested. Overall, T. cruzi antibody prevalence was 1.88% (nine patients). Five were onco-hematological patients, two were hemodialyzed, one had thalassemia, and one had suffered acute blood loss. We found no hemophilia patients. There was no association between known risk factors for transfusion-transmitted infection (such as the number of transfusion events, number of blood units and type of blood component) and the presence of anti-T. cruzi antibodies in this study. Only the hepatitis C virus infection showed a positive association with the presence of anti-T. cruzi antibodies (OR=5.68, 95% CI: 1.36-23.63).

CONCLUSIONS

The results of this study showed a low frequency of T. cruzi infection in multitransfused patients, suggesting that the risk of transfusion infection in Colombia is low. Known risk factors for transfusion-related infection were not associated with the presence of anti-T. cruzi antibodies.

Chagas disease in Europe: A review for the internist in the globalized world

Chagas disease (CD) or American trypanosomiasis identified in 1909 by Carlos Chagas, has become over the last 40years a global health concern due to the huge migration flows from Latin America to Europe, United States, Canada and Japan. In Europe, most migrants from CD-endemic areas are concentrated in Spain, Italy, France, United Kingdom and Switzerland. Pooled seroprevalence studies conducted in Europe show an overall 4.2% prevalence, with the highest infection rates observed among individuals from Bolivia (18.1%). However, in most European countries the disease is neglected with absence of screening programmes and low access to diagnosis and treatment. Physicians working in Europe should also be aware of the risk of autochthonous transmission of Trypanosoma cruzi to newborns by their infected mothers and to recipients of blood or transplanted organs from infected donors. Finally, physicians should be able to recognize and treat the most frequent and serious complications of chronic Chagas disease, namely cardiomyopathy, megacolon and megaesophagus. This review aims to highlights the problem of CD in Europe by reviewing papers published by European researchers on this argument, in order to raise the awareness of internists who are bound to increasingly encounter patients with the disease in their routine daily activities.

Pheophorbide a, a compound isolated from the leaves of Arrabidaea chica, induces photodynamic inactivation of Trypanosoma cruzi

BACKGROUND

Approximately 6-7 million people are infected with Trypanosoma cruzi, the etiological agent of Chagas' disease. Only two therapeutic compounds have been found to be useful against this disease: nifurtimox and benznidazole. These drugs have been effective in the acute phase of the disease but less effective in the chronic phase; they also have many side effects. Thus, the search for new compounds with trypanocidal action is necessary. Natural products can be the source of many important substances for the development of drugs to treat this infection. The present study evaluated the biological activity of an extract and fractions of Arrabidaea chica against T. cruzi and observed morphological and ultrastructural characteristics of parasites exposed to the isolated compound pheophorbide a.

METHODS

The crude hydroethanolic extract of A. chica was prepared. Fractions were obtained by partition and separated by liquid chromatography.

RESULTS

We observed a progressive increase in activity against epimastigote, trypomastigote, and amastigote forms of the parasite over the course of the fractionation process. Interestingly, we isolated a compound known as a photosensitizer that is used in photodynamic therapy. This method of treatment involving a photosensitizer, activation light and molecular oxygen is of great importance due to its selectivity. Pheophorbide a had activity against the protozoan in the presence of light and caused morphological and ultrastructural changes, demonstrating its potential in photodynamic therapy.

CONCLUSIONS

Based on the ability of pheophorbide a to eliminate bloodstream forms of T. cruzi, we suggest its use in blood banks for hemoprophylaxis.

Frequency of Trypanosoma cruzi parasitemia among infected blood donors with a potential association between parasite lineage and transfusion transmission

BACKGROUND

Trypanosoma cruzi is endemic to the Americas where it demonstrates multiple lineages over a vast geographic range (i.e., United States to Argentina). These lineages possess divergent geographic and biologic characteristics, including variations in disease manifestations. Herein, we report the frequency of parasitemia among seropositive US blood donors and the potential association between parasite lineage and transfusion transmission.

STUDY DESIGN AND METHODS

Blood donors identified as T. cruzi seropositive during screening were enrolled in follow-up studies, including hemoculture testing and a risk factor questionnaire. Positive hemocultures were expanded to obtain sufficient parasites for molecular lineage determination and analysis. Country of birth, obtained from the questionnaire, was used to predict parasite lineage in the absence of demonstrable parasitemia for infected donors.

RESULTS

Eighteen (6.8%) of 263 seropositive donors were hemoculture positive. Among the 17 hemocultures expanded for lineage determination, TcV was identified more frequently (n = 12), compared to TcI (n = 2), TcII (n = 1), and TcVI (n = 2). When presumptive parasite lineages were compared to hemoculture results, only two of 157 (1.3%) TcI versus 13 of 38 (34.2%) TcII/TcV/TcVI non-US donors were parasitemic; three of 44 (6.8%) US donors were TcV or TcVI.

CONCLUSIONS

Based on lineage determination for donors with parasitemia; hemoculture positivity associated with presumptive parasite lineage; and implicated donors from US, Canadian, and Spanish transfusion cases, donors from Southern South America are significantly more likely to have parasitemia and transmit infection to blood recipients (TcII, TcV, or TcVI vs. TcI). Thus, parasite lineage may be associated with risk of transfusion-transmitted T. cruzi.

A Case of Possible Chagas Transmission by Blood Transfusion in Switzerland

BACKGROUND

Transfusion-transmitted Chagas disease has been reported from endemic countries in Latin America. Switzerland is a non-endemic country but high prevalence of antibodies against Trypanosoma cruzi was found among immigrants. Immigrants may participate in blood donation; therefore, risk-adapted anti-T. cruzi screening for blood donors was implemented in Switzerland in 2013.

METHODS

Between January 2013 and July 2015, 1 out of 1,183 at-risk donors, tested at Blood Transfusion Service Zurich, was found anti-T. cruzi IgG-positive.

RESULTS AND CONCLUSION

Out of 54 donations given by the index donor (ID), we identified 77 blood products which were delivered to hospitals. Archived serum samples from the donations given during the prior 5 years were available for retrospective testing. All samples from ID revealed positive findings for anti-T. cruzi IgG. Donor-triggered look-back procedure identified a 70-year-old male recipient of a platelet concentrate (PC) donated by ID. The recipient succumbed of acute T. cruzi infection 2 years after transfusion of the PC.

Chagas disease and transfusion medicine: a perspective from non-endemic countries

In the last decades, increasing international migration and travel from Latin America to Europe have favoured the emergence of tropical diseases outside their "historical" boundaries. Chagas disease, a zoonosis endemic in rural areas of Central and South America represents a clear example of this phenomenon. In the absence of the vector, one of the potential modes of transmission of Chagas disease in non-endemic regions is through blood and blood products. As most patients with Chagas disease are asymptomatic and unaware of their condition, in case of blood donation they can inadvertently represent a serious threat to the safety of the blood supply in non-endemic areas. Since the first cases of transfusion-transmitted Chagas disease were described in the last years, non-endemic countries began to develop ad hoc strategies to prevent and control the spread of the infection. United States, Spain, United Kingdom and France first recognised the need for Trypanosoma cruzi screening in at-risk blood donors. In this review, we trace an up-to-date perspective on Chagas disease, describing its peculiar features, from epidemiological, pathological, clinical and diagnostic points of view. Moreover, we describe the possible transmission of Chagas disease through blood or blood products and the current strategies for its control, focusing on non-endemic areas.

Selective Testing of At-Risk Blood Donors for Trypanosoma cruzi and Plasmodium spp. in Switzerland

BACKGROUND

Population migrations and overseas recreational travel to regions at risk for tropical diseases are increasing. A major challenge in non-endemic countries is to decrease the number of blood donor deferrals due those tropical disease pathogens, without compromising the high level of blood safety. The protozoans Trypanosoma cruzi and Plasmodium spp., the causative organisms of Chagas disease (CD) and malaria are becoming a major focus in the blood transfusion community.

METHODS

National guidelines of the Blood Transfusion Service of the Swiss Red Cross propose an algorithm for dealing with these pathogens, including a mandatory selective serological testing of donors at risk.

RESULTS

6,978 donors at risk for CD were tested. Three of them were confirmed anti-T. cruzi -positive, and in one case a transfusion-transmitted infection was highly possible. The specificity of the assay was 99.94%. For malaria 12,887 donors were at risk and 178 were confirmed positive. The specificity of the assays was 92.8%.

CONCLUSION

CD and malaria in non-endemic countries may represent a certain risk for blood transfusion. Switzerland chose a selective testing approach. The specificity of the assays is a crucial topic for this approach because it ensures a minimal loss of false-reactive donors and helps towards an easier counselling of implicated donors.

Prevalence of Chagas disease in the Bolivian population of Majorca (Spain)

OBJECTIVE

To establish the prevalence of Trypanosoma cruzi infection in Bolivian (Spain) participants.

METHODS

A cross sectional study was carried out in Majorca. Bolivian residents older than 18 years assigned to the family physicians of two primary care centers were randomly selected from the health card population database. Participants were invited to attend a serology test and an interview. T. cruzi infection was confirmed after two positive ELISA tests. If the result was positive or dubious, the serological test was sent to the National Microbiology Center for confirmation.

RESULTS

A total of 251 participants were included (response rate 36.3%). The overall seroprevalence of Chagas infection was 19.1% (95% CI: 14.06-24.19). Seroprevalence was higher in participants from highly endemic provinces, those from rural areas, those who had lived in mud houses, and in those whose mother or a family member had contracted this infection.

CONCLUSION

This study demonstrates a high prevalence of T. cruzi in Bolivian residents, which was strongly associated with established risk factors.

Prevalence of Chagas disease in Latin-American migrants living in Europe: a systematic review and meta-analysis

BACKGROUND

Few studies have assessed the burden of Chagas disease in non-endemic countries and most of them are based on prevalence estimates from Latin American (LA) countries that likely differ from the prevalence in migrants living in Europe. The aim of this study was to systematically review the existing data informing current understanding of the prevalence of Chagas disease in LA migrants living in European countries.

METHODS

We conducted a systematic review and meta-analysis of studies reporting prevalence of Chagas disease in European countries belonging to the European Union (EU) before 2004 in accordance with the MOOSE guidelines and based on the database sources MEDLINE and Global Health. No restrictions were placed on study date, study design or language of publication. The pooled prevalence was estimated using random effect models based on DerSimonian & Laird method.

RESULTS

We identified 18 studies conducted in five European countries. The random effect pooled prevalence was 4.2% (95%CI:2.2-6.7%); and the heterogeneity of Chagas disease prevalence among studies was high (I2 = 97%,p<0.001). Migrants from Bolivia had the highest prevalence of Chagas disease (18.1%, 95%CI:13.9-22.7%).

CONCLUSIONS

Prevalence of Chagas in LA migrants living in Europe is high, particularly in migrants from Bolivia and Paraguay. Data are highly heterogeneous dependent upon country of origin and within studies of migrants from the same country of origin. Country-specific prevalence differs from the estimates available from LA countries. Our meta-analysis provides prevalence estimates of Chagas disease that should be used to estimate the burden of disease in European countries.

[Blood transfusion: control of infectious risks]

From blood donor collection to transfusion of the recipient, there are several layers of protection of the blood supply. These measures combined with huge progresses over the three past decades in pathogen discovery and blood testing for specific pathogens (human immunodeficiency virus (HIV), hepatitis B (HBV) and C (HCV) viruses, Human T-cell leukemia virus (HTLV)), provide the greatest safety. With the implementation of serological and molecular testing, at least in high-income countries, transfusion-transmitted infections have become extremely rare. However, for pathogen agents, which are not tested and especially those which are responsible for emerging infectious disease, it became apparent that full control of infectious disease had not been achieved. In addition, the immune status of the recipient has also an impact in the outcome of infectious diseases transmitted by transfusion. Blood safety is based on several measures: education and deferral of donors with risk factors for transmissible disease, blood testing, pathogen reduction interventions, and patient blood management. This paper proposes a review of the residual risk of transmission of infectious diseases by transfusion and of the additional interventions able to further reduce it.

Trypanosoma cruzi calreticulin inhibits the complement lectin pathway activation by direct interaction with L-Ficolin

Trypanosoma cruzi, the agent of Chagas' disease, the sixth neglected tropical disease worldwide, infects 10-12 million people in Latin America. Differently from T. cruzi epimastigotes, trypomastigotes are complement-resistant and infective. CRPs, T-DAF, sialic acid and lipases explain at least part of this resistance. In vitro, T. cruzi calreticulin (TcCRT), a chaperone molecule that translocates from the ER to the parasite surface: (a) Inhibits the human classical complement activation, by interacting with C1, (b) As a consequence, an increase in infectivity is evident and, (c) It inhibits angiogenesis and tumor growth. We report here that TcCRT also binds to the L-Ficolin collagenous portion, thus inhibiting approximately between 35 and 64% of the human complement lectin pathway activation, initiated by L-Ficolin, a property not shared by H-Ficolin. While L-Ficolin binds to 60% of trypomastigotes and to 24% of epimastigotes, 50% of the former and 4% of the latter display TcCRT on their surfaces. Altogether, these data indicate that TcCRT is a parasite inhibitory receptor for Ficolins. The resulting evasive activities, together with the TcCRT capacity to inhibit C1, with a concomitant increase in infectivity, may represent T. cruzi strategies to inhibit important arms of the innate immune response.

Multicenter epidemiological and clinical study on imported Chagas diseases in Alicante, Spain

Recently, there has been an increase in the number of patients with Chagas disease outside of areas that are generally considered endemic. The aim of this investigation is to describe the clinical profile of a series of patients with Chagas disease in Alicante, Spain, which is a province located on the coast of the Mediterranean Sea. This study was performed at four general hospitals in Alicante between January 2002 and May 2011. A total of 128 patients from seven countries were diagnosed with Trypanosoma cruzi. The main country of origin of these patients was Bolivia (n5101; 78.9%), and the median of age of these patients was 35 years (range: 0–72 years). Four (3.3%) patients were children under 14 years of age, and 81 (63.3%) were female. Polymerase chain reaction (PCR) was used to analyze 106 patients, 66.0% of whom demonstrated positive PCR results. Visceral involvement was diagnosed in 26.8%: 24.1% demonstrated cardiac involvement, 0.9% demonstrated gastrointestinal involvement, 0.9% demonstrated cardiac and gastrointestinal involvement, and 0.9% demonstrated involvement of the central nervous system. Syncope was found to be associated with cardiomyopathy (28.0% versus 5.2%) (odds ratio: 6.5; 95% confidence interval: 1.5–27.1). Seventy-six patients received treatment with benznidazole, of whom 57 (75.0%) completed the treatment course without significant adverse events and 17.1% discontinued benznidazole due to adverse events. In total, 50% of patients experienced documented adverse reactions. Among patients with positive PCR results before treatment, all demonstrated negative PCR results following treatment. In conclusion, majority of our patients were female Bolivians immigrants, one of four of our patients demonstrated cardiac involvement, and treatment tolerance was poor. It is important to improve the clinical and epidemiological knowledge of Chagas disease in nonendemic with additional multicenter studies in order to determine the magnitude of this problem and provide improved public health and health resource planning.

Trypanosoma cruzi infection in Elche (Spain): comparison of the seroprevalence in immigrants from Paraguay and Bolivia

Chagas disease is a global public health problem due to the recent emigration of people from Latin America to other regions, including Europe. The aim of this study is to determine the prevalence of Trypanosoma cruzi infection among Paraguayans and Bolivians living in Elche (Spain), a city located in the Mediterranean Coast of Spain. A cross-sectional study was conducted. Capillary blood samples were obtained through a finger prick, and collected on filter paper. An enzyme-linked immunosorbent assay and indirect immunofluorescence tests were performed to search for anti-T. cruzi IgG antibodies in the filter papers. Thirteen out of 201 participants were infected with T. cruzi in this study, seven out of 73 Bolivians and six out of 128 Paraguayans, corresponding to seroprevalences of 9·59% (95%CI, 4·72-18·5%) and 4·69% (95%CI, 2·17-9·85%), respectively. Palpitation, chest pain, and migration from rural endemic areas were the most common clinical and epidemiological risk factors associated with T. cruzi infection detected in the Paraguayan group. This study highlights that Chagas disease is no longer limited to the Bolivian population living in Spain. It is important to note this wider prevalence and, therefore, not discount Paraguayans in the screening for Chagas disease in Spain. Indeed, this should be considered for all immigrants from Latin America.

American trypanosomiasis

American trypanosomiasis is a parasitic disease caused by the flagellate protozoan Trypanosoma cruzi. Chagas disease is endemic in Latin America, where an estimated 10-14 million people are infected, and an emerging disease in Europe and the USA. Trypanosoma cruzi is transmitted by blood-sucking bugs of the family Reduviidae. Rhodnius prolixus, Panstrongylus megistus, Triatoma infestans, and T. dimidiata are the main vectors in the sylvatic cycle. Non vector-borne transmission includes blood transfusion, congenital and oral transmission, transplantation, and accidental infections. Most cases of acute infection occur in childhood and are usually asymptomatic, although severe myocarditis and meningoencephalitis may occur. Approximately 30% of T. cruzi-infected people will develop the chronic stage of the disease. Chronic chagasic cardiomyopathy is characterized by progressive heart failure, arrhythmias, intraventricular conduction defects, sudden death, and peripheral thromboembolism. Acute exacerbation can occur in individuals with involvement of cellular immunity such as advanced AIDS (acquired immunodeficiency syndrome), and transplant-associated immunosuppression. Neurological involvement may present with encephalitis, meningoencephalitis, or a space-occupying cerebral lesion called chagoma. Chagas disease is a major cause of ischemic stroke in Latin America. Several epidemiological studies have found an association between T. cruzi infection and cardioembolic ischemic stroke. Benznidazole and nifurtimox are the two available trypanocide drugs against T. cruzi.

Sensitivity and specificity of an operon immunochromatographic test in serum and whole-blood samples for the diagnosis of Trypanosoma cruzi infection in Spain, an area of nonendemicity

Trypanosoma cruzi infection is an imported parasitic disease in Spain, and the majority of infected individuals are in the chronic phase of the disease. This study evaluated the sensitivity and specificity of the Operon immunochromatographic test (ICT-Operon; Simple Stick Chagas and Simple Chagas WB [whole blood]; Operon S.A., Spain) for different biological samples. Well-characterized serum samples were obtained from chagasic patients (n = 63), nonchagasic individuals (n = 95), visceral leishmaniasis patients (n = 38), and malaria patients (n = 55). Noncharacterized specimens were obtained from Latin American immigrants and individuals at risk with a clinical and/or epidemiological background: these specimens were recovered serum or plasma samples (n = 450), whole peripheral blood (n = 94), and capillary blood (n = 282). The concordance of the results by enzyme-linked immunosorbent assay and indirect immunofluorescence test was considered to be the "gold standard" for diagnosis. Serum and plasma samples were analyzed by Stick Chagas, and whole blood was analyzed by Simple Chagas WB. The sensitivity and specificity of the ICT-Operon in well-characterized samples were 100% and 97.9%, respectively. No cross-reactivity was found with samples obtained from visceral leishmaniasis patients. In contrast, a false-positive result was obtained in 27.3% of samples from malaria patients. The sensitivities of the rapid test in noncharacterized serum or plasma, peripheral blood, and capillary blood samples were 100%, 92.1%, and 86.4%, respectively, while the specificities were 91.6%, 93.6%, and 95% in each case. ICT-Operon showed variable sensitivity, depending on the kind of sample, performing better when serum or plasma samples were used. It could therefore be used for serological screening combined with any other conventional test.

Identification of a Western blot pattern for the specific diagnosis of Trypanosoma cruzi infection in human sera

A Western blot (WB) method using a lysate from Trypanosoma cruzi (Maracay strain) epimastigotes was evaluated. Serum samples from 37 patients with confirmed Chagas disease (cohort I), 27 Spanish patients with visceral leishmaniasis caused by Leishmania infantum (cohort II), and 28 Colombian patients with cutaneous leishmaniasis caused by L. panamensis and negative serology for Chagas disease (cohort III) were tested. The negative controls were 55 healthy seronegative subjects for T. cruzi and Leishmania; 28 of the negative controls were from a region endemic for Chagas disease and Leishmania (cohort IV), and 27 of the negative controls were from a non-endemic area for Leishmania and T. cruzi (cohort V). A homogeneous standard band pattern consisting of six antigenic bands corresponding to 28, 32, 38, 39, 40, and 48 kDa was recognized simultaneously for all Chagasic patients' sera. Sera from Leishmania-infected patients showed a heterogeneous band pattern that was easily differentiated from the pattern of patients with Chagas disease. WB with T. cruzi epimastigote antigen is an efficient method for diagnosis and may be used as an alternative to confirm T. cruzi and detect cross-reactivity with Leishmania.

Trypanosoma cruzi infection in North America and Spain: evidence in support of transfusion transmission

BACKGROUND

The United States, Canada, and Spain perform selective testing of blood donors for Trypanosoma cruzi infection (Chagas disease) to prevent transfusion transmission. The donor, product, and patient characteristics associated with transfusion-transmitted infections are reviewed and the infectivity of components from donors with serologic evidence of infection is estimated.

STUDY DESIGN AND METHODS

A systematic review of transfusion-transmitted T. cruzi cases and recipient tracing undertaken in North America and Spain is described. Cases were assessed for the imputability of the evidence for transfusion transmission.

RESULTS

T. cruzi infection in 20 transfusion recipients was linked to 18 serologically confirmed donors between 1987 and 2011, including 11 identified only by recipient tracing. Cases were geographically widely distributed and were not associated with incident or autochthonous infections. Index clinical cases were described only in immunocompromised patients. All definite transmissions (n = 11) implicated apheresis or whole blood-derived platelets (PLTs), including leukoreduced and irradiated products. There is no evidence of transmission by red blood cells (RBCs) or frozen products, while transmission by whole blood transfusion remains a possibility. Recipient tracing reveals low component infectivity from serologically confirmed, infected donors of 1.7% (95% confidence interval [CI], 0.7%-3.5%) overall: 13.3% (95% CI, 5.6%-25.7%) for PLTs, 0.0% (95% CI, 0.0%-1.5%) for RBCs, and 0.0% (95% CI, 0%-3.7%) for plasma and cryoprecipitate.

CONCLUSIONS

T. cruzi is transmitted by PLT components from some donors with serologic evidence of infection. Evidence of transmission before the implementation of widespread testing in the countries studied is sparse, and selective testing of only PLT and fresh whole blood donations should be considered.

Lack of association between blood-based detection of Trypanosoma cruzi DNA and cardiac involvement in a non-endemic area

Cases of chronic Chagas disease have been increasing in non-endemic areas due to the growth in immigration. This study examined the association between positive Trypanosoma cruzi-DNA detection in blood by PCR and presence of chagasic cardiac involvement in a cohort of immigrants in a European city. No association was found in this study between the positive T. cruzi blood PCR and cardiac involvement.

Gastro-intestinal Chagas disease in migrants to Spain: prevalence and methods for early diagnosis

Each year in Spain, the number of Latin American immigrants who present with chronic Trypanosoma cruzi infection increases. Although gastro-intestinal abnormalities are not as common as cardiomyopathy in such infection, they can still lead to an impaired quality of life. In a recent study based in Madrid, the frequencies of gastro-intestinal involvement in a cohort of Latin American immigrants infected with T. cruzi, and the role of early diagnostic techniques in the detection of such involvement, were explored. Between January 2003 and April 2009, all Latin Americans who attended the Tropical Medicine Unit of the Hospital Universitario Ramón y Cajal were tested for T. cruzi infection, in IFAT and ELISA. Each subject found both IFAT- and ELISA-positive was considered to be infected (chronically) and checked for symptoms indicative of Chagas disease. Each infected subject giving informed consent was investigated further, using an electrocardiogram, an echocardiogram and oesophageal manometry. Between January 2003 and June 2008, every infected subject who consented was also explored using a barium swallow and barium enema. After July 2008, however, only subjects showing oesophageal and/or colonic symptoms were investigated in this manner. Of the 248 patients found infected with T. cruzi, 118 underwent oesophageal manometry, 75 a barium enema and 48 a barium swallow. Thirteen (11%) showed evidence of oesophageal involvement (incomplete relaxation of the lower oesophageal sphincter; three cases) or bowel involvement (five cases of dolichosigma, three of dolichocolon and two of megacolon). Only six of these 13 had any gastro-intestinal symptoms (all six were suffering from constipation). None of the barium swallows revealed any pathology. It appears that oesophageal manometry can reveal mild abnormalities not detected by barium swallow, even in asymptomatic patients, while barium enemas are useful in the detection of colonic involvement.

Organ donor screening practices for Trypanosoma cruzi infection among US Organ Procurement Organizations

Donor-derived Trypanosoma cruzi infection in solid organ transplant recipients is associated with significant morbidity and mortality. Little is known about T. cruzi screening practices among U.S. organ procurement organizations (OPOs). We distributed a questionnaire to all U.S. OPO directors, requesting data on T. cruzi screening strategies, laboratory methods, number of donors screened, disposition of organs from positive donors and attitudes toward screening. Fifty-eight (100%) U.S. OPOs responded to the survey. Donor screening began in 2002 and is presently performed by 11 (19%) OPOs. Among screening OPOs, four screen all donors and seven use a risk-based strategy. Three different T. cruzi serology tests are used for donor screening. During 2008, 9/993 (0.9%) donors screened positive by a T. cruzi screening test, 6/9 (66%) had confirmatory tests performed and 4/6 (66%) had positive confirmatory tests. These results led to the nonuse of five donors and 17 organs. Five organs from three seropositive donors were transplanted in 2008 without recognized disease transmission. Variability of T. cruzi donor screening strategies, laboratory methods and disposition of organs from positive donors currently exists. Further research is needed to identify the risk of donor-derived T. cruzi infections to help inform the best screening strategy.

[Chagas disease and blood transfusion: an emerging issue in non-endemic countries]

Chagas disease or American human trypanosomiasis, is a parasitic disease due to Trypanosoma cruzi, which is endemic in Latin America. The parasite is transmitted by haematophagous vectors from reduviidae family. In some patients, the parasite is responsible for severe complications such as cardiac manifestations, gastrointestinal involvement and neurologic disease. Imported Chagas disease by immigration in non-endemic countries poses the threat of the infection transmission by blood transfusion. In order to prevent this risk, the French Blood Services (EFS) introduced systematic screening of at-risk blood donors for anti-T. cruzi antibodies, in May 2007. The concerned donors are people originating from an endemic area, donors with mothers originating from such an area and individuals who had lived in or travelled to endemic areas. Donors were screened with two different Elisas simultaneously: one Elisa using purified parasite lysate antigens and the second one composed of recombinant antigens. Positive results and discrepant results were further assayed with an immunofluorescence assay. A seroprevalence assay was performed in the 17 French blood centres after an 18-month testing period from May 2007 to December 2008. During this period 4,637,479 million donations were collected. Out of these 163,740 donations were tested (3.5%). The prevalence of anti-T. cruzi antibodies was one in 32,800 donations. Five positive donors were identified. All of them were originating from endemic areas. A rate of 0.85% indeterminate results was found. Screening strategy revision was decided to reduce the number of donors unnecessarily deferred.

Chagas disease: a Latin American health problem becoming a world health problem

Political repression and/or economic stagnation stimulated the flow of migration from the 17 Latin American countries endemic for Chagas disease to developed countries. Because of this migration, Chagas disease, an autochthonous disease of the Continental Western Hemisphere is becoming a global health problem. In 2006, 3.8% of the 80,522 immigrants from those 17 countries to Australia were likely infected with Trypanosoma cruzi. In Canada in 2006, 3.5% of the 156,960 immigrants from Latin America whose country of origin was identified were estimated to have been infected. In Japan in 2007, there were 80,912 immigrants from Brazil, 15,281 from Peru, and 19,413 from other South American countries whose country of origin was not identified, a portion of whom may have been also infected. In 15 countries of Europe in 2005, excluding Spain, 2.9% of the 483,074 legal Latin American immigrants were estimated to be infected with T. cruzi. By 2008, Spain had received 1,678,711 immigrants from Latin American endemic countries; of these, 5.2% were potentially infected with T. cruzi and 17,390 may develop Chagas disease. Further, it was estimated that 24-92 newborns delivered by South American T. cruzi infected mothers in Spain may have been congenitally infected with T. cruzi in 2007. In the USA we estimated that 1.9% of approximately 13 million Latin American immigrants in 2000, and 2% of 17 million in 2007, were potentially infected with T. cruzi. Of these, 49,157 and 65,133 in 2000 and 2007 respectively, may have or may develop symptoms and signs of chronic Chagas disease. Governments should implement policies to prevent donations of blood and organs from T. cruzi infected donors. In addition, an infrastructure that assures detection and treatment of acute and chronic cases as well as congenital infection should be developed.

Chagas disease in Spain, the United States and other non-endemic countries

Due to recent trends in migration, there are millions of people from Chagas disease-endemic countries now living in North America, Europe, Australia and Japan, including thousands of people with Trypanosoma cruzi infection. Most infected individuals are not aware of their status. Congenital, transfusion- and/or transplant-associated transmission has been documented in the United States, Spain, Canada and Switzerland; most instances likely go undetected. High priorities include the implementation of appropriate screening, evaluation and clinical management, and better assessment of the true burden associated with this disease.

Transfusion transmitted Chagas disease: is it really under control?

Transfusion transmitted Chagas disease was recognized as a medical problem more than 50 years ago. However, little attention was paid to it by Transfusion Medicine, medical authorities or regulatory agencies as a major problem and threat (especially after the advent of HIV/AIDS); perhaps because it was mainly restricted to tropical regions, usually in less developed countries. With the intense human migratory movement from developing to developed countries, it became more common and evident. The scope of this review is to cover the main transfusional aspects of American trypanosomiasis (Chagas disease), including the main strategies to prevent it through donor questionnaires, specific serological testing and alternative methods such as leukofiltration and pathogen reduction procedures, in order to increase the blood safety in both developing and developed countries.

Screening for Chagas' disease in HIV-positive immigrants from endemic areas

Chagas' disease is an opportunistic infection in the setting of HIV/AIDS. The arrival of HIV-positive immigrants from endemic areas to non-endemic countries makes possible the detection of Chagas' disease in this group of patients. We describe the results of a screening programme conducted in the HIV-positive immigrant population arriving from endemic areas who attended the Tropical Medicine Unit of Hospital Universitario Central of Asturias during 2008. We determined anti-T. cruzi antibodies in all HIV patients arriving from endemic areas who were followed up. The ID-Chagas antibody test was used as a screening assay. The positive cases were confirmed with ELISA, IFAT and PCR. We analysed 19 HIV-positive immigrants, of which two (10·5%) had a positive antibody test for Chagas' disease confirmed. PCR was positive in both cases. There was no difference between the co-infected and the non-co-infected patients with respect to race, place of birth and residence, CD4+ cell count, and HIV viral load count. Direct microscopic examination of blood was negative in both positive cases. The positive patients were a man from Bolivia and woman from Paraguay. The overlap of HIV and T. cruzi infection occurs not only in endemic areas but also in non-endemic areas of North America and Europe where the diagnosis may be even more difficult due to low diagnostic suspicion. The implementation of screening programmes in this population group is needed for the early diagnostic of Chagas' disease.